GB2229756A

GB2229756A - Testing anchoring device

Info

Publication number: GB2229756A
Application number: GB8906106A
Authority: GB
Inventors: John Thomas Chambers
Original assignee: Baker and Finnemore Ltd
Current assignee: Baker and Finnemore Ltd
Priority date: 1989-03-16
Filing date: 1989-03-16
Publication date: 1990-10-03
Anticipated expiration: 2009-03-16
Also published as: GB2229756B; GB8906106D0

Abstract

An anchoring device, such as a remedial wall tie, has spaced anchorages 5, 15, eg. for engagement in the leaves of a cavity wall, which can be separately tested for security in a hole or holes. The anchorages are at aligned first and second, tubular, members, 1, 2 having an interconnection 13, 14 permitting limited movement between them in the direction of their alignment. The first member 1 is releasably connectable to a testing device for applying loads to that member to test its anchorage 5, and to the second member 2 through the first member and interconnection to test the anchorage 15 of the second member. If the anchorage of the first member is insufficiently secure the interconnection 13, 14 allows that member to move relative to the second member under the testing load, thereby making the unsecurity apparent at the testing device. In one embodiment one anchorage has laterally movable dogs 21, 23 to grip the hole or holes and the other anchorage is secured by synthetic resin, and in another embodiment both anchorages have dogs. <IMAGE>

Description

ANCHORING DEVICE This invention relates to an anchoring device for providing a fixing in a wall, floor or other structure and particularly though not exclusively, to a wall tie for connecting the inner and outer leaves of cavity walls of buildings.

Wall ties embedded in the mortar courses are incorporated during the building of brick or block cavity walls. In many older buildings the original wall ties of steel have been weakened by rusting to such an extent that they have broken or are dangerously weak. Replacement is necessary. It is possible by removing bricks to replace old wall ties by new ones similarly embedded in mortar, but this is a very laborious and time consuming process.

Remedial wall ties have been provided as an alternative which are fitted into and secured in holes drilled through one leaf, usually the outer leaf, and partway through the other leaf, usually the inner leaf. Various forms of remedial wall-ties have been proposed. Some involve the use of synthetic resin to secure the tie and/or nut elements or gripping means in the leaves of the wall. It is essential that the wall ties are secure in both leaves of the wall and desirable that the security of the wall ties in both leaves can be tested.

There may be other uses of anchoring devices having spaced anchorages in a hole or aligned holes in which it is desirable to test the security of the anchorages.

The present invention seeks to provide an anchoring device having spaced anchorages which can be separately tested for security.

According to the present invention an anchorage device is provided comprising aligned first and second members interconnected to permit limited relative movement between them in the direction of their alignment and having anchorage means adapted to be engaged at axially spaced positions in a hole or aligned holes in a structure and being individually securable in the hole or holes to anchor the device therein, and the first member having means for releasably connecting a testing device thereto whereby when the anchorage device is fitted for use the security of the anchorage means in the hole or holes can be tested by the application of loads on the members in the direction of their alignment.The arrangement is such that when the second member is secured by its anchorage means in the hole or one of the holes such a load can be applied to the second member by way of the first member by means of the testing device to test the security- of the anchorage means of the second member, and when the anchorage means of the first member is subsequently secured in the hole or another one of the holes and a load as aforesaid is applied to the first member by means of the testing device the interconnection between the members allows the first member to move relative to the second member under the load of the anchorage means if the first member is insufficiently secure. The movement of the first member indicates that its anchorage is insecure.

In the testing of the anchorage means of each of the members, if there is movement of the anchorage means under a load applied by the means of the testing device it may be indicated by a drop in the reading on a load gauge of the testing device, and/or by movement of another indicator of, or associated with, the testing device which may be suitably graduated to show the extent of the movement of the member which has its anchorage means under test.

The anchorage means may be adapted to be secured in the hole or the respective holes by bonding by a synthetic resin, by nut elements or by gripping means which are urged laterally into gripping engagement with the surface of the hole or holes. In one embodiment of the invention in its application to a remedial wall-tie the anchorage means of the one member is adapted to be secured by a synthetic resin, and the anchorage means of the other member comprises gripping means and a plunger which is operably connected to the gripping means and is movable in the direction of the alignment of the first and second members to project the gripping means into gripping engagement with the surface of the perspective hole in the leaf of the cavity wall engaged by that other member.The member having the anchorage means adapted to be secured by a synthetic resin may comprise a tubular body including a windowed portion having an aperture or apertures through the material of the tubular body with which the synthetic resin can key. In accordance with our British Patent Application No. 8825701, the windowed portion may be contracted radially of the tubular body to form a waisted portion of the body so that, in use, on fitting the anchoring device in the hole, or respective hole, substantial local clearance is left between the windowed portion and the surface of the hole for synthetic resin used to secure the member in the hole.

The other member may also have a tubular body or sleeve and the gripping means may comprise transverse dogs disposed in openings in the wall of the body or sleeve. The plunger may be operably connected to the gripping means by having at least one inclined portion engageable with the dogs.

The interconnection between the first and second members permitting the relative movement between them may comprise male and female elements or formations engaging transversely of the direction of alignment of the members and with clearance in the direction of alignment to allow for the required limited movement.

For example a projection on the one member may engage in an over-sized groove or slot in the other.

When the anchorage device is a remedial wall-tie the interconnection typically permits approximately 2-3 mm relative movement between the first and second members in the direction of their alignment.

In the wall-tie form the first member is preferably adapted to engage in the hole in the leaf of the cavity wall, usually the outer leaf, at which the wall-tie is introduced into the wall, and the second member engages in the aligned hole in the other leaf, usually the inner leaf, of the wall. Accordingly the wall-tie is preferably designed to be secured in the latter leaf first and then in the former leaf. It would be possible for the device to be arranged for the members to be engaged the opposite way round in the leaves.

Testing devices for remedial wall-ties are usually provided with an internally screw-threaded socket to engage 6mm screw-threaded ends of wall ties of the rod type. To enable the security of a wall-tie according to the present invention to be tested by standard equipment, an adaptor may be provided having a 6mm screw-threaded shank and a spigot. The first member may have a tubular portion complementary to the spigot into which the spigot fits. Interengaging formations may be provided on the spigot and that tubular portion engageable on insertion of the spigot into the tubular portion. For example, the spigot may be inserted axially and then turned to cause the formation to interengage. The adaptor is secured to the wall-tie by the interengaging formations and the testing device is connected to the adaptor by the screw-threaded shank.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which, Figure 1 is an underneath plan view of an anchoring device in accordance with the invention in the form of a remedial wall-tie; Figure 2 is a vertical axial section through the wall-tie of Figure 1 which is shown in an operative condition; Figure 3 is a side view of another anchoring device in accordance with the present invention also in the form of a remedial wall-tie, being shown in an operative condition; and Figure 4 is a vertical axial section through the wall-tie of Figure 3.

Referring to Figures 1 and -2 of the drawings, the wall-tie shown comprises an outer member 1, a co-axial inner member 2, a plunger 3, guide bushes 4, 4' and a gripper sub-assembly 5. All of these components are made of stainless steel. They could alternatively be made of other materials of adequate strength and either inherently resistant to corrosion or protected against corrosion.

The outer member 1 comprises a sleeve 6 formed from stainless steel strip rolled over transversely into a tube of circular cross-section with a narrow longitudinal gap, not shown, between the longitudinal edges of the strip. Two diametrically opposed arcuate, parallel-sided openings 7, 7' are cut-through the wall of the sleeve 6 at an intermediate part of its length to receive the gripper sub-assembly 5, one of the openings, 7', traversing the narrow gap. Two diametrically opposed inwardly projecting lugs 8 are punched out of the wall of the sleeve near an outer end of the sleeve.

The inner member 2 comprises a tubular body 9 and a rod 10 fast with and projecting co-axially from an outer end of the body 9. The body 9 is formed similarly to the sleeve 6 of the outer member 1 from stainless steel strip rolled over into a tube with a narrow longitudinal gap, not shown, between the longitudinal edges of the strip. It is shorter than the sleeve 6. For the most part the body is of very slightly smaller diameter than the sleeve. The rod 10 is an interference fit in the body and the two are rigidly secured together by the engagement of a chordal indentation 11 in the wall of the body in an annular groove 12 of complementary width in the circumference of the rod. At its free end the rod 10 slidably engages co-axially in the bore of an inner end of the sleeve 6.The extent of the sliding movement of the rod 10 in the sleeve, and hence of the relative axial movement allowed between the outer member 1 and the inner member 2, is limited by an internal chordal lug 13 of the sleeve, punched from the wall of the sleeve opposite the narrow gap, engaging in a wider annular groove 14 formed in the circumference of the rod near its free end. The body 9 is axially spaced from the sleeve 6 by the rod 10.

Beyond the fast end of the rod 10 the body 9 of the inner member 2 has at an intermediate portion 15 angularly spaced, narrow, longitudinal strips 16 formed and separated from one another by piercing round-ended slots 17 forming elongated windows 18 through the material of the body. The strips 16 are bent radially inwards in a wide symmetrical V-shape until their edges meet, or nearly so, at the inner ends of the V-shapes.

Each window 18 therefore narrows from its ends towards the point where the edges of the strips 16 between which it is formed meet, or are closest together. The body 9 of the inner member is given a waisted form at the intermediate portion 15.

A rubber O-ring 19 is fitted on the rod 10 intermediate the sleeve 6 and the body 9 to serve as a moisture barrier when the wall-tie is in use to prevent moisture passing from the sleeve of the outer member to the body of the inner member.

The gripper sub-assembly 5, as stated, is mounted in the sleeve of the outer member 1 at the openings 7, 7'. It is made up of five face-to-face plates 20, 21, 22, 23, 24 all having the same external dimensions and the shape of a notional circular disc from which segments have been removed to form a pair of straight, parallel edges spaced apart to fit freely between diametrically opposed bridging portions 25 of the wall of the sleeve 6 separating the openings 7, 7'. The plates all have similar square apertures, not shown, two opposite sides of which are parallel to the parallel edges of the plates. The apertures of the plates 20, 22 and 24, which are guide plates, are central between the curved ends of the plates but those in the other two plates 21 and 23, which are dog plates interposed between the guide plates, are eccentrically disposed.The dog plates 21, 23 are assembled so that their longer portions form the apertures extend in opposite directions. The assembled guide and dog plates are a free sliding fit between the arcuate parallel sides of the openings 7, 7' and are supported in position across the sleeve by the engagement of the ends of the axially innermost and outermost guide plates 20, 24 with the arcuate edges of the openings 7, 7'.

Plunger 3 is made from rectangular section bar which is a free sliding fit in the apertures of the guide and dog plates. It is supported centrally in the sleeve 6 by the guide bushes 4, 4' which fit in the bore of the sleeve and have internal diameters affording clearance on the diagonal dimension of the cross-section of the plunger 3 so that the plunger is free to move axially in the guide bushes. There are two of the guide bushes 4, 4' at opposite sides of the gripper sub-assembly 5. Nylon "0" rings 26, 26' are fitted in the sleeve in abutment with the outer ends of the two guide bushes 4, 4', the "0" ring 26' against which the axially innermost guide bush 4' abuts is sandwiched between that guide bush and the adjacent innermost guide plate 24.

Two inclined portions 27 are formed on opposite faces of the plunger 3 toward its inner end providing a wedge-shaped region tapering towards, but not to, the inner end. The plunger 3 is inserted through the guide bushes 4, 4' and the apertures of the guide and dog plates 20 - 24 of the gripper sub-assembly 5 with the inclined portions 27 facing in the direction of the openings 7, 7' of the sleeve. Until the wall-tie is required to be used the plunger is inserted just sufficiently for the inclined portions 27 to be in loose engagement with the apertures of the guide and dog plates so that the plates are free to move laterally in this position of the plunger. A band of adhesive tape may be applied over the openings 7, 7' to prevent the plates from projecting out of the openings during installation of the wall-tie.

To install the wall-tie a hole, of a complementary diameter to the sleeve 6, is drilled through an outer leaf 28 of a cavity wall and part-way through an inner leaf 29. The leaves 28, 29 are separated by a cavity 30. The hole is drilled deeper than the over-all length of the wall-tie. Resin is then injected into the blind hole in the inner leaf 29 and the wall-tie is pushed as far as it will go into the hole. The tubular body 9 of the inner member 2 enters the blind-hole and the resin flows through the windows 18 enveloping the body in resin. The sleeve of the outer member is received into the outer leaf, lining the hole in that leaf except for an outer end portion 31 of the hole.

When the resin has set the waisted portion 15 of the tubular body affords a good key ensuring that the inner member is rigidly secured in the inner leaf. The rod 10 extends across the cavity 30 to the sleeve of the outer member 1. The O-ring 19 on the rod 10 is positioned in the cavity and provides a barrier to moisture passing between the two leaves 28, 29 along the rod. Moisture reaching the O-ring 19 can drip off the O-ring down into the cavity.

As the wall-tie is pushed into the hole there is relative axial movement of the outer and inner members towards one another permitted by the interengagement of the chordal lug 13 of the sleeve and the groove 14 of the rod 10.

When the resin has set the security of the inner member in the inner leaf 29 can be tested before the outer members is secured in the outer leaf. The testing is done by fitting an adaptor, not shown, to the outer end of the sleeve and connecting a testing device, not shown, of a known kind, to the adaptor.

The adaptor has a spigot with a head at its free end which is inserted into the outer end of the sleeve and, by turning the spigot, engaged behind the lugs 8. The testing device is connected by screwing a threaded shank of the adaptor into a mating internally threaded socket of the testing device. Through the adaptor the testing device exerts a pull on the sleeve which initially moves axially outwards relative to the inner member until the play between the lug 13 of the sleeve and the groove 14 of the rod 10 has been taken up.

Once the clearance has been taken up the pull is applied also to the inner member and the tension applied can be measured by the testing device to show that the anchorage of the inner member in the inner leaf is within prescribed limits.

Before the outer member 1 can be secured in the outer leaf 28 the outer member has first to be pushed inwards until the play between the lug 13 and the groove 14 is taken up in that direction. The plunger 3 is then driven inwards, using a drift inserted into the sleeve. As the inclined portions 27 drivingly engage with the plates 20 - 24 the dog plates 21, 23 are caused to be projected by the inclined portions 27 out through the openings 7, 7', as shown in Figure 2, and to dig into the surface of the hole in the outer leaf, thereby tying the inner and outer leaves of the cavity wall together. The plunger is driven inwards until the inclined portions 27 have passed right through the plates and the apertures in all of the plates are occupied by the full cross-section of the plunger.

Thus the dog plates are held projected and there is no force tending to move the plunger outwards against.

When the plunger has been driven inwards the full extent its inner end abuts against the free end of the rod.

The security of the outer member in the outer leaf can be tested by again fitting the adaptor to the sleeve and exerting a pull on the sleeve by the testing device connected to the adaptor. The pull acts on the dog plates. If the grip of the dog plates in the hole is not sufficiently secure and is unable to withstand the pull applied by the testing device within the prescribed limits, the dog plates will slip in the hole, the play available between the lug 13 of the sleeve and the groove 14 of the rod allowing the sleeve to move axially outwards relative to the inner member under the pull. The shift of the sleeve is indicated on the testing device by a drop in the load reading.

If the test on the security of the outer member is satisfactory the outer end portion 31 of the hole is filled with mortar or mastic to cover and protect the exposed end of the wall-tie.

In the embodiment illustrated by Figures 3 and 4 of the drawings the wall-tie is provided with two spaced gripper sub-assemblies which respectively engage in the inner and outer leaves of a cavity wall to secure the wall-tie in position in that manner, rather than using resin as in the foregoing embodiment. The wall-tie comprises a two-part sleeve 36, a plunger 37, four guide bushes 38, 39, 40, 41 and the two gripper sub-assemblies 42, 43.

The two-part sleeve has axially inner and outer parts, 44 and 45 respectively, of the same diameters and formed from stainless steep strip rolled over into tubular form in the manner previously described in respect of the sleeve 6. The inner part 44 is longer than the outer part 45. They are connected together by a lap-and-scarf butt joint 46 having a gap 47 between notched portions 48 of the two parts 44, 45 at the joint which permits limited relative axial movement between the inner and outer parts.

Each of the gripper sub-assemblies 42, 43, one in the inner part 44 of the sleeve and the other in the outer part 45, is of the form previously described comprising three guide plates 49 separated by two interposed dog plates 50. The plates, all apertured as before, are located in openings 51 in the walls of the respective sleeve parts.

The plunger 37, again made from rectangular-section bar, is a free sliding fit in the apertures of the plates of both gripper sub-assemblies 42, 43 and is supported centrally in the two sleeve parts 44, 45 by the guide bushes 38, 39, 40, 41 arranged in two pairs, one pair in each sleeve part at opposite sides of the gripper sub-assembly of that part. Nylon O-rings 52 are fitted in the outer sleeve part 45 at opposite ends of the guide bushes 38, 39 in that part. Two axially spaced pairs of inclined portions 53, 54 are formed on the plunger 37 for projecting the dog plates 50 of the respective gripper sub-assemblies 42, 43 in the manner previously described when the plunger is driven axially inwards along the two-part sleeve.The positioning of the pairs of inclined portions 53, 54 is such that the gripper sub-assembly 43 of the inner sleeve portion and the gripper sub-assembly 42 of the outer sleeve part 45 are operated simultaneously when the plunger is driven inwards.

A drip washer 55 is fitted on the plunger 37 in the inner sleeve part opposite windows 56 cut into the wall of that sleeve part. The drip washer 55 is positioned so that when the wall-tie is installed in a cavity wall the washer will be disposed in the cavity and any moisture reaching it, from either side, can drip off through the windows 56 into the cavity.

Inwardly projecting lugs 57 are punched out of the wall of the outer sleeve part near its outer end for the attachment of an adaptor for connecting a testing device, as before, to the wall-tie.

For installation of the wall-tie, a hole of complementary diameter to the two-part sleeve, and longer than the sleeve, is drilled through the outer leaf and part-way into the inner leaf of the cavity wall. The wall-tie is pushed as far as it will go into the hole, the inner sleeve part engaging in the inner leaf and the outer sleeve part engaging in the outer leaf. Then the plunger is driven into the sleeve to project the dog plates 50 of the gripper sub-assemblies at the inner and outer sleeve parts into gripping engagement with the surface of the hole in the inner and outer leaves respectively. The security of the anchorage in the outer leaf can be tested by fitting the adaptor to the outer sleeve and applying a pull by means of the testing device through the adaptor.If the anchorage is not sufficiently secure to hold under the tension applied by the testing device the dog plates slip in the hole and the outer sleeve moves axially outwards relative to the inner sleeve part, the gap 47 allowing that movement which is sufficient to indicate at the testing device that the wall-tie is not properly secure in the outer leaf. If it is secure there will be no movement of the outer sleeve part and the gap 47 will remain at the joint 46. In order to test the security of the anchorage at the inner sleeve in the inner leaf the load applied by the testing device is increased until the gripper assembly of the outer sleeve slips in the outer leaf. The gap 47 of the joint 46 between the two sleeve parts allows the outer sleeve part to move axially outwards relative to the inner sleeve part under the applied pull. Once the movement allowed by that gap has been taken up the testing pull is exerted on the inner sleeve part and the grip of the dog plates of its gripper sub-assembly in the hole can thus be tested to ensure that it is within prescribed limits. The small extent of the forced slip of the outer sleeve part in the outer leaf under the excess applied load as the gap 47 is opened still leaves the outer sleeve part secured, and is therefore acceptable.

The plunger is subsequently driven further inwards to project the dog plates 50 of the gripper sub-assembly at the outer sleeve part 45, and so secure the wall-tie to the outer leaf of the cavity wall.

Driving the plunger inwards initially moves the outer sleeve part axially. Security of the anchorage at the outer leaf can be similarly tested by the testing device.

In both of the embodiments described the extent of the relative axial movement permitted between the inner and outer members of the first embodiment and the inner and outer sleeve parts of the second embodiment is limited, typically, to approximately 1.4mm.

Whilst wall-ties have been described and illustrated, it will be understood that their features may be used in generally similar anchoring devices for securing together structural components and separately testing the security of the anchorages provided.

Claims

1. An anchoring device comprising aligned first and second members, an interconnection between the members which permits limited relative movement between the members in the direction of their alignment, and anchorage means at the members adapted to be engaged at axially spaced positions in a hole or aligned holes in a structure and being individually securable in the hole or holes to anchor the device therein, the first member having means for releasably ' connecting a testing device thereto whereby when the anchoring device is fitted for use the security of the anchorage means in - the hole or holes can be tested by the application of loads on the members in the direction of their ,alignment, the arrangement being such that when the first member is secured by its anchorage means in the ole or one of the holes such a load can be applied to the first member by means of the testing device to test the security of the anchorage means of the first member, the interconnection between the members allowing the first member to move relative to the second member under the testing load if the anchorage means of the first member is insufficiently secure and when the anchorage means of the second member is secured in the hole or another one of the holes a load as aforesaid can be applied to the second member by way of the first member and the interconnection by means of the testing device to test the security of the anchorage means of the second member.

2. An anchoring device according to claim 1 wherein at least at one cf the members the anchorage means is adapted to be secured in the hole or one of the holes by bonding by a synthetic resin.

3. An anchoring device according to claim 2 wherein the or each anchorage means adapted to be secured by bonding by a synthetic resin comprises a tubular body including a windowed portion having an aperture or apertures through the material of the tubular member with which the synthetic resin can key.

4. An anchoring device according to claim 3 wherein the windowed portion is contracted radially of the tubular body to form a waisted portion of the body so that, in use, on fitting the anchoring device in the hole or holes substantial local clearance is left between the windowed portion of the surface of the, or the respective, hole for synthetic resin used to secure the, or the respective member, in the hole.

5. An anchoring device according to claim 1 wherein at least at one of the members the anchorage means is adapted to be secured in the hole or one of the holes by a nut element.

6. An anchoring device according to claim 1 wherein at least at one of the members the anchorage means is adapted to be secured in the hole or one of the holes by gripping means adapted to be urged laterally into gripping engagement with the surface of the hole, or of one of the holes.

7. An anchoring device according to claim 6 wherein a plunger is operably connected to the gripping means and is movable in the direction of the alignment of the first and second members to urge the gripping means laterally into gripping engagement with the surface of the hole, or of one of the holes.

8. An anchoring device according to claim 7 wherein the or each anchorage means adapted to be secured by the gripping means comprises a tubular body or sleeve, and the gripping means comprises transverse dogs disposed in openings in the wall of the body or sleeve and laterally movable by the plunger to project from the openings for gripping engagement with the surface of the hole, or of one of the holes.

9. An anchoring device according to claim 8 wherein the plunger is operably connected to the gripping means by having at least one inclined portion engageable with apertures in the dogs, whereby as the inclined portion moves through the apertures its engagement with the apertures causes the dogs to be moved laterally of the plunger.

10. An anchoring device according to any of claims 2 to 4 and also according to any one of claims 6 to 9 wherein one of the members has its anchorage means adapted to be secured in the hole or one cf the holes by bonding by a synthetic resin, and the other member has its anchorage means adapted to be secured in the hole or another one of the holes by the gripping means.

11. An anchoring device according to any one claims 6 to 9 wherein both members have their anchorage means adapted to be secured in the hole or holes by the gripping means.

12. An anchoring device according to any preceding claim wherein the interconnection between the first and second members comprises male and female elements or formations engaging transversely of the direction of alignment of the members and with clearance in the direction of alignment to allow for the required limited movement between the members.

13. An anchoring device according to claim 12 wherein the interconnection comprises a projection on one of the members engaged in an over-sized groove or slot in the other member.

14. An anchoring device according to claim 13 wherein the members are tubular and are connected by a rod which extends into adjacent ends of the tubular members, is anchored to one of the members against movement relative thereto and has a groove in the other member in which an internal lug of that other member engages, the groove being wider than the lug in the direction of alignment of the members thereby to allow the limited movement between the members.

15. An anchoring device according to claim 12 wherein the members are tubular and the interconnection between them comprises a lap-and-scarf butt joint between adjacent ends of the members having a gap between notched portions of the members which permits limited axial movement between the members.

16. An anchoring device according to any preceding claim in combination with an adaptor which connects to a testing device and has a spigot, and wherein the means of the first member for releasably connecting the testing device to the member comprises a tubular portion complementary to the spigot into which the spigot fits, and the tubular portion and the spigot have formations which interengage when the spigot is inserted in the tubular portion to secure the adaptor to the first member against relative movement between the adaptor and the first member in the direction of alignment of the first and second members.

17. An anchoring device according to any preceding claim which is a remedial wall tie.

18. An anchoring device according to claim 17 as dependent from claim 14 wherein the members are spaced apart by the rod for respective engagement of the members in the opposite leaves of a cavity wall with the rod extending across the cavity between the leaves, and the rod has a moisture barrier intermediate the members adapted to prevent moisture from passing from one member to the other along the rod.

19. An anchoring device according to claim 17 as dependent from any of claims 7 to 9 wherein the members are adapted to engage in the opposite leaves of a cavity wall, the plunger is positioned to extend across the cavity between the leaves in use of the device in a cavity wall, and the plunger has a moisture barrier positioned to be disposed in the cavity when the device is in use and adapted to prevent moisture from passing along the plunger from one leaf to the other of the cavity wall.

20. An anchoring device according to claim 19 wherein one of the members is tubular and is adapted to extend across the cavity when the device is in use in a cavity wall, the plunger extends inside that member, and window means is provided in that member adjacent to the moisture barrier through which moisture can drip from the barrier into the cavity in use of the device.

21. A method of testing the security of an anchoring device as claimed in any preceding claim when fitted for use in a hole or holes, comprising the steps of securing the second member by its anchorage means in the hole or one of the holes, connecting a testing device to the first member and applying on the first member by means of the testing device loading which, when the extent of the relative movement between the members permitted by the interconnection in one direction has been taken up, is applied through the interconnection also to the second member and measured by the testing device, or an indicator associated with the testing device, to test that the anchorage means of the second member is withstanding the applied load within desired limits, disconnecting the testing device and remedying the security of the anchorage means of the second member if it is unsatisfactory or, if the security is satisfactory, moving the first member relative to the second member in the opposite direction by the extent permitted by the interconnection, securing the first member by its anchorage means in the hole or another one of the holes, re-connecting the testing device to the first member, and applying test loading on the first member by the testing device, which loading is measured by the testing device or indicator and if the anchorage means of the first member is secure within desired limits is withstood by the anchorage means but if the anchorage means of the first member is insufficiently secure causes the first member to move relative to the second member within the extent allowed by the interconnection, which makes the insecurity apparent at the testing device or indicator.

22. A method of testing the security of an anchoring device as claimed in claim 11 when fitted for use in a hole or holes, comprising the steps of arranging that the interconnection between the members will permit relative movement between the members in a direction in which test loading is to be applied to the device, securing the first member by its anchorage means in the hole or one of the holes, connecting a testing device to the first member and applying on the first member by means of the testing device test loading which is measured by the testing device, or an indicator associated with the testing device, to test that the anchorage means of the first member is withstanding the applied load within desired limits, disconnecting the testing device and remedying the security of the anchorage means of the first member if it is unsatisfactory or, if the security is ' satisfactory, securing the second member by its anchorage means in the hole or another one of the holes, re-connecting the testing device to the first member, applying a higher loading on the first member by the testing device sufficient to cause the anchorage means of the first member to slip under the loading and allow the first member to move relative to the second member in the said direction sufficiently to take up the extent of the movement arranged to be permitted by the interconnection, and applying a test loading then by the testing device through the interconnection to the second member, which loading is measured by the testing device or indicator and if the anchorage means of the second member is secure within desired limits is withstood by the anchorage means but if the anchorage means of the second member is insufficiently secure causes the second member to move relative to the first member which makes the insecurity apparent at the testing device or indicator.

23. An anchoring device substantially as described herein with reference to Figures 1 and 2 of the accompanying drawings.

24. An anchoring device substantially as described herein with reference to Figures 3 and 4 of the accompanying drawings.